How do you get the css with bundle.generate?

[matt-way]

I am using rollup dynamically with bundle.generate(), and while it provides the correct .css.js files in the output array, there is no .css file returned. If I test with bundle.write it writes the css file correctly. I've tried different postcss config, but cannot get rollup to return the css.

Is there a way to do this, or is this a bug?